On percussion instruments, a drum stand usually is used to hold drums of different sizes. Referring to FIG. 1, a conventional drum has an upper side and a lower side coupled respectively with an upper drum rim a and a lower drum rim b, and a plurality of lugs c attached annularly on the drum shell at the upper side and lower side. The upper drum rim a and each lug c at the upper side of the drum shell are fastened by a bolt d longitudinally running through the lug c to hold an upper drum head of the drum tightly. Similarly, the lower drum rim b and each lug c at the lower side of the drum shell also are fastened by another bolt d longitudinally running through the lug c to hold a lower drum head of the drum tightly. A conventional drum and drum stand coupler includes an upper coupler 1 and a lower coupler 2. The upper coupler 1 has a top and the lower coupler 2 has a bottom that are extended horizontally leftwards and rightwards in an arched manner to form a wing 3. The wing 3 has a slot running through up and down and coupled with an elastic pad 4. The pad 4 has a longitudinal hole run through by the bolt d to engage with the lug c to fasten the drum and the coupler together. The upper coupler 1 further has a plate 5 extended longitudinally downwards. The plate 5 has side plates 6 respectively on the left side and right side bent towards the drum. Each side plate 6 has a longitudinal sliding slot. The lower coupler 2 has a pair of upright planks 7 located longitudinally upwards on the left side and right side to be disposed on the inner side of the side plate 6 in a staggered manner. The upright plank 7 has a strut 8 on an outer side coupled in the sliding slot. The side plate 6 has a bolt 9 on an outer side running through the sliding slot to fasten the upright plank 7. Thus the upper coupler 1 and the lower coupler 2 can be fastened together. The plate 5 further is fastened to a fixture f on the surface to couple with a drum stand (not shown in the drawing).
The drums of different sizes generate different sound, and the drum height and the size of the drum shell impacts the sound. The coupler has to couple with drums of varying heights and different drum shells and also couple to a drum stand. The conventional coupler previously discussed can adjust only the elevation distance of the upper and lower couplers 1 and 2, but is not adaptable to the drum shells of greater size differences.